Nail Biters May Develop Fewer Allergies

Babies have been seen sucking on their fingersin utero weeks before birth. But the sight of an older child with his fingers constantly in his mouth, sucking her thumb, biting his nails, can drive parents crazy, bringing up fears about everything from social stigma to germs.

A new study suggests that those habits in children ages 5 to 11 may indeed increase exposure to microbes, but that that may not be all bad.

In astudy published Monday in the journal Pediatrics, researchers drew evidence from an ongoing study of New Zealand children to show those whose parents described them as thumb-suckers and nail-biters were less likely to have positive allergic skin tests later in life.